William johnson



alwt illili Letters Patent No. 93,889, dated August 17, 1869.

DVIPRO'VEMENT IN STEAM-CYLINDER PISTON-PACK'ING..

The Schedule referred to in these LettersY Patent' and making part of the same.

To all whom fit may concern:

Be it known that I, WILLIAM J OILNSON, ofthe town of Lambertville, in the county of Hunterdon, and State oi' New Jersey, have invented a new and improved Piston for Steam-Enginfes, Pumps, 65o.; and I do hereby declare that the following is a full and exact description thereof, reference beinghad to the accompanying drawings, and t0 the letters of' reference marked.

thereon.

My invention consists, briefly, in fitting two circular plates to slide upon the hub or body of the piston, between the ange of the piston-head and follower-plate.

These circular plates have a lim projecting around their outside, which, when fitted together, form an annular groove around the hub of the piston, in which i usual manner, are heldfinplace by the follower and iiange-plates, while the bevelled edges of the springplates, forced apart by means of the springs between them, open or spread the packing-rings out against vthe cylinder at every point alike, thereby holding the piston precisely central with the bore of the cylinder.

AIn the accompanying drawings- Figure lis an end View of piston, with the followerplate, one packing-ril ig, and oneV spring-plate removed, showing the position of springs.

Figure 2 is a .longitudinal sectional view, showing the relation of all the parts.

The several letters in all the igures refer to the same parts.

A is theange, or piston-head, secured firmly to rod K.

B, follower-plate.

O O, the narrow' packingfrings.

S S S S S S, the springs.

E E, screws, to hold the follower-plate.

R R, the circular spring-plates. What I claim as my invention, an'd wish to secure by Letters Patent, is

The packhig-rings O O, having one edge bevelled, incombination withl the circular spring-plates R R, having corresponding bevelled edges, when combined and arranged in the manner substantially as described and set forth.

XVM. JOHNSON. Yv'itnesses GHAs'. A. SKILLMAN, ALEX. Stevens.- 

